Ratchet devices are commonly used to drive a fastener, such as a bolt or nut, especially where the fastener is located in a restricted area. When the fastener is not accessible from all sides, a wrench or other similar tool cannot likely engage the fastener and rotate 360° with respect to the fastener to drive the fastener. Thus, the wrench must be removed each time it engages an obstruction so that it may be resituated on the fastener to continue driving the fastener in the appropriate direction.
A ratchet is designed to drive a fastener in a restricted area without removing the ratchet from the fastener. A ratchet includes a socket that engages and transmits torque to the fastener. The torque is transmitted to the socket member by moving the ratchet in a rotary motion. With a standard ratchet, the fastener is tightened or loosened only on the drive stroke, and not on the return stroke. The ratchet typically includes a positioning system that allows the ratchet to tighten or loosen the fastener in the drive direction, and transmits no appreciable torque in the opposite return stroke direction. On the drive stroke, the ratchet transmits torque to the fastener, and on the return stroke, the positioning system enables the ratchet body to rotate about the socket. Accordingly, the ratchet need not be removed from the fastener to return the ratchet to its original position because no torque is transmitted to the socket or fastener on the return stroke.